He lived for music, hunting down strange videos and tinkering with broken-down objects.

L.A., he thought, would let him grow as an artist, free to explore without stricture.

He came to CalArts to study photography, but he wasn't one to stay on the path.

For his senior project, which was photo-less, he improvised on a piano in a public gallery and built an art installation in which casts of his arms held a backyard hot tub in the air.

After graduation, he went home to South Salem, N.Y. But L.A. kept tugging.

So in the fall of 2011, Sam came back — still safely in that twilight of youth, before the full weight of the future presses in.

On South Serrano Avenue in Koreatown, in a 1920s Spanish-style building called the Sir Francis Drake, he found a studio apartment and a perfect small world.

Here were people who, like him, were game to wake up and hike Griffith Park, to bike the city late at night while others slept, and to search out the taco trucks he loved.

He grew so close to the two guys who lived in the apartment right above his that he set up a window-to-window tin-can telephone system.

Most evenings, he could be found on their rooftop patio, watching the sun sink over palm trees, a netted golf range, glass office towers.

Then a year ago, in the place he loved so much, Sam was stabbed to death.

Around 12:45 a.m. on April 10, 2012, he walked home alone from R Bar, about five blocks away. Around 2:30 a.m., neighbors heard scuffles and screams. When police arrived at his fifth-floor apartment, he was able to tell them to come in. Seconds later, he was dead.

He was 25 years old.

His killer has not been found.

The police say they have little to go on. There was no sign of forced entry. Nothing appears to have been stolen.

They've found no motive, no indication that anyone wished to do Sam harm.

Usually, said LAPD Det. Rolando Rodriguez, you hear that so-and-so was a nice guy, but.... With Sam, he said, he's heard no "buts" — from anyone.

Rodriguez hopes to locate one particular person who might know something — described by witnesses as a male, either white or Latino, who was seen in the area on a BMX bike.

Imagine being a parent pleased to hear that your child is happy, even though you might rather have him nearer. You support him. You send him off on his adventures. Then comes the terrible knock on the door.

Sam was the first-born child of Deborah and Bruce Michel.

He was their dreamer, their overgrown baby boy.

They hadn't had a chance to visit their son since he'd moved back to L.A.

So their first sight of the Sir Francis Drake, which he'd told them so much about, was as the scene of his brutal murder.

This week, they returned with their 24-year-old son, Lucas, even though being where Sam was killed makes them crumple and weep.

Their daughter, Hannah, 22, could not face coming.

But the Michels felt their presence was needed.

Last summer, the city offered a $50,000 reward for information about Sam's death. The family just doubled it — hoping to raise public awareness of the case.

They also hired a party planner, sent invitations to everyone in the building's 61 units, and posted fliers welcoming the neighborhood.

On the afternoon of the first anniversary of their son's death, at the Sir Francis Drake, they held a celebration of Sam's life.

In the courtyard his apartment looked out on, a DJ and a trumpet player filled the air with gentle jazz. Photos of Sam smiling were everywhere — on the walls, on blown-up copies of the reward sign, on a slide show playing on a computer left open on a table, next to 25 balloons, one for each year of his life.

At curbside, a taco truck offered up free helpings of the food he loved.

Many LAPD officers came. As Heidi Stoecklein, a senior lead officer, described picking Deborah Michel up at the airport after the murder, her eyes welled. Stoecklein's own boys are 6 and 3, she said. She flipped over her badge to show a photo of them stuck on the back.

The Michels and police said they hoped the gathering might bring forth new information. Just in case, Deborah hired a photographer to document the event and security guards to watch the crowd.

She said she had to stop herself from leaving her Santa Monica hotel in the middle of the night to stand outside the building at the time her son was killed, just in case his killer was drawn back to the scene.

Soon after the murder, a neighborhood watch was launched. Five people moved out of the building. But many who knew Sam remain.

Nawana Davis, 70, teaches sky yoga on the roof. Sam made fliers for her, she said, and she saw him on the roof just about every day. "He was just a beautiful human being, a loving spirit," she said.

In the courtyard, Deborah handed each person she met a small silver elephant. The message: Do not forget.

As the sun began to drop and tears slid down cheeks, no one seemed in any danger of doing so.